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authorTrond Myklebust <trond.myklebust@primarydata.com>2016-09-22 13:39:13 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-09-27 14:35:00 -0400
commit1393d9612ba02d8bb8dae1dab319807e92354fe3 (patch)
treeac86090ed9e1071285e875ecc16503c5c3fe62fc /fs/nfs
parentb1a318de9bc4946ad4a20481ab3ce28c2e8cd72c (diff)
downloadlinux-1393d9612ba02d8bb8dae1dab319807e92354fe3.tar.bz2
NFSv4: Fix a race when updating an open_stateid
If we're replacing an old stateid which has a different 'other' field, then we probably need to free the old stateid. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Tested-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4proc.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d1e60c915a07..389089e857f4 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1399,11 +1399,12 @@ static void nfs_test_and_clear_all_open_stateid(struct nfs4_state *state)
}
static bool nfs_need_update_open_stateid(struct nfs4_state *state,
- nfs4_stateid *stateid)
+ const nfs4_stateid *stateid, nfs4_stateid *freeme)
{
if (test_and_set_bit(NFS_OPEN_STATE, &state->flags) == 0)
return true;
if (!nfs4_stateid_match_other(stateid, &state->open_stateid)) {
+ nfs4_stateid_copy(freeme, &state->open_stateid);
nfs_test_and_clear_all_open_stateid(state);
return true;
}
@@ -1467,7 +1468,9 @@ static void nfs_clear_open_stateid(struct nfs4_state *state,
nfs4_schedule_state_manager(state->owner->so_server->nfs_client);
}
-static void nfs_set_open_stateid_locked(struct nfs4_state *state, nfs4_stateid *stateid, fmode_t fmode)
+static void nfs_set_open_stateid_locked(struct nfs4_state *state,
+ const nfs4_stateid *stateid, fmode_t fmode,
+ nfs4_stateid *freeme)
{
switch (fmode) {
case FMODE_READ:
@@ -1479,14 +1482,18 @@ static void nfs_set_open_stateid_locked(struct nfs4_state *state, nfs4_stateid *
case FMODE_READ|FMODE_WRITE:
set_bit(NFS_O_RDWR_STATE, &state->flags);
}
- if (!nfs_need_update_open_stateid(state, stateid))
+ if (!nfs_need_update_open_stateid(state, stateid, freeme))
return;
if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
nfs4_stateid_copy(&state->stateid, stateid);
nfs4_stateid_copy(&state->open_stateid, stateid);
}
-static void __update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stateid, const nfs4_stateid *deleg_stateid, fmode_t fmode)
+static void __update_open_stateid(struct nfs4_state *state,
+ const nfs4_stateid *open_stateid,
+ const nfs4_stateid *deleg_stateid,
+ fmode_t fmode,
+ nfs4_stateid *freeme)
{
/*
* Protect the call to nfs4_state_set_mode_locked and
@@ -1499,16 +1506,22 @@ static void __update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_s
set_bit(NFS_DELEGATED_STATE, &state->flags);
}
if (open_stateid != NULL)
- nfs_set_open_stateid_locked(state, open_stateid, fmode);
+ nfs_set_open_stateid_locked(state, open_stateid, fmode, freeme);
write_sequnlock(&state->seqlock);
update_open_stateflags(state, fmode);
spin_unlock(&state->owner->so_lock);
}
-static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stateid, nfs4_stateid *delegation, fmode_t fmode)
+static int update_open_stateid(struct nfs4_state *state,
+ const nfs4_stateid *open_stateid,
+ const nfs4_stateid *delegation,
+ fmode_t fmode)
{
+ struct nfs_server *server = NFS_SERVER(state->inode);
+ struct nfs_client *clp = server->nfs_client;
struct nfs_inode *nfsi = NFS_I(state->inode);
struct nfs_delegation *deleg_cur;
+ nfs4_stateid freeme = {0};
int ret = 0;
fmode &= (FMODE_READ|FMODE_WRITE);
@@ -1530,7 +1543,8 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat
goto no_delegation_unlock;
nfs_mark_delegation_referenced(deleg_cur);
- __update_open_stateid(state, open_stateid, &deleg_cur->stateid, fmode);
+ __update_open_stateid(state, open_stateid, &deleg_cur->stateid,
+ fmode, &freeme);
ret = 1;
no_delegation_unlock:
spin_unlock(&deleg_cur->lock);
@@ -1538,11 +1552,14 @@ no_delegation:
rcu_read_unlock();
if (!ret && open_stateid != NULL) {
- __update_open_stateid(state, open_stateid, NULL, fmode);
+ __update_open_stateid(state, open_stateid, NULL, fmode, &freeme);
ret = 1;
}
if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags))
- nfs4_schedule_state_manager(state->owner->so_server->nfs_client);
+ nfs4_schedule_state_manager(clp);
+ if (freeme.type != 0)
+ nfs4_test_and_free_stateid(server, &freeme,
+ state->owner->so_cred);
return ret;
}